Active Flux and Polygons: why a stabilisation and how to implement boundary conditions
Abstract
In a recent paper, the authors developed an Active Flux-type algorithm for polygonal meshes (see \cite{BP_Pampa_VEM}). The main difference between Active Flux methods on polygonal meshes and those on Cartesian or simplex meshes is that the basis functions are not explicitly known. These functions describe the solution using point-value approximations on the polygon boundaries and the average value within the polygons. In \cite{BP_Pampa_VEM}, it was shown that directly transposing the algorithm from simplexes to polygons leads to a mild instability, and a remedy was proposed without a rigorous explanation. In the present paper, we clarify this issue and demonstrate that the solution presented in \cite{BP_Pampa_VEM} is indeed correct. Furthermore, another challenge-the implementation of boundary conditions-was previously solved heuristically. Building on \cite{pampa_dg}, we show how to properly implement these boundary conditions. Finally, the method is illustrated through several examples with hybrid meshes.
Related
- Carleman estimates for a nonconservative Timoshenko beam involving Dirichlet-Neumann boundary conditions and application to exact controllability
- Classification of boundary blow-ups for the Mumford-Shah functional with Dirichlet boundary conditions
- On the spectrum of the biharmonic Steklov operator with Neumann boundary conditions acting on forms of the unit Euclidean ball
- The Three-Dimensional Divergence-Curl Problem with Homogeneous Boundary Conditions and Pseudo-Harmonic Fields
- Existence and multiplicity results for third-order ordinary differential equations with derivative dependence subject to the Riemann–Stieltjes integral boundary conditions
BibTeX
@misc{abgrall2026active,
title = {{Active Flux and Polygons: why a stabilisation and how to implement boundary conditions}},
author = {Remi Abgrall and Yongle Liu},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.34761},
eprint = {2610.34761},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.34761},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - UNPB
TI - Active Flux and Polygons: why a stabilisation and how to implement boundary conditions
AU - Remi Abgrall
AU - Yongle Liu
PY - 2026
DA - 2026/10/26
PB - arXiv
DO - 10.48550/arxiv.2610.34761
UR - https://arxiv.org/abs/2610.34761
AB - In a recent paper, the authors developed an Active Flux-type algorithm for polygonal meshes (see \cite{BP_Pampa_VEM}). The main difference between Active Flux methods on polygonal meshes and those on Cartesian or simplex meshes is that the basis functions are not explicitly known. These functions describe the solution using point-value approximations on the polygon boundaries and the average value within the polygons. In \cite{BP_Pampa_VEM}, it was shown that directly transposing the algorithm from simplexes to polygons leads to a mild instability, and a remedy was proposed without a rigorous explanation. In the present paper, we clarify this issue and demonstrate that the solution presented in \cite{BP_Pampa_VEM} is indeed correct. Furthermore, another challenge-the implementation of boundary conditions-was previously solved heuristically. Building on \cite{pampa_dg}, we show how to properly implement these boundary conditions. Finally, the method is illustrated through several examples with hybrid meshes.
ER -